This invention is directed to apparatus for facilitating depositing of sheets in a stacking bin such that a larger number of sheet formats can be reliably deposited and unobstructedly aligned.
Copending U.S. patent application Ser. No. 07/615,115, filed Nov. 19, 1990 relates to an apparatus for depositing sheets, particularly copy sheets produced by a copier, which are individually fed into a bin and collected there in stacked relation. The bin has a depositing surface and a stop means for registering the leading edge of the incoming sheets and at least one guide element arranged opposite said stop means and directing the sheet fed to the bin onto those already deposited. A device, located above the sheet stack to be formed and within the collecting bin, includes at least one stationary roller associated with the trailing portion of the sheet stack facing the guide element and is driven in sheet entry direction. The surface facing the sheet stack lies beneath the entry plane of the sheets determined by the guide element to the extent that it limits the top and trailing portion, respectively, of the sheet stack in a recessed position beneath the sheet entry plane, keeping the feed path open.
Utilizing the apparatus according to the aforementioned U.S. patent application, it is possible to confine several sheet formats within a limited range of sheet formats in a recessed position, keeping the feed path open. This is effected by means of a guide element and a roller or a series of rollers provided in the trailing portion of the deposited sheets. Depending on the setting of the sheet format to be processed, it is also possible in the above apparatus to move the rollers from an inoperative position to an operative position associated with the trailing portion of the sheet stack to be formed.
In an apparatus of the above-described type, a number of very different sheet formats are to be processed, e.g., long sheets entering in longitudinal direction (DIN A3), short sheets (DIN A5) or sheet entering (transversely) with their longer edge (DIN A4) as well as further sheet formats entering longitudinally or transversely. However, when the apparatus is set to the smallest sheet format (DIN A5) or when sheet formats enter transversely, the sheets drop into the collecting bin over a very long path without being appropriately guided so that they may take a canted position that cannot be corrected prior to the arrival of the following sheet.